1. Field of the Invention
The present invention pertains to the art of packaging and, more specifically, to a system for repetitively opening and sealingly closing an openable end of a pliable container, such as a bag, as well as a method and apparatus for producing a pliable container with a closure system.
2. Discussion of the Prior Art
Pliable or flaccid containers are widely used to store both edible and non-edible products. For example, snack items, such as various types of chips and cereals, are typically packaged in pliable containers. These containers are generally sealed at both ends for initial packaging purposes and then one of the ends is opened to access the product. It is often desirable to utilize the container to store the product for extended periods of time and to repetitively open and close one end of the container to selectively access the contents thereof.
When used to store edible food items, it is particularly advantageous to adequately seal the openable end of the container between uses in order to prolong the useful life of the food items stored therein. For this reason, once the initial seal at one end of the container is broken, it is common practice to roll up the openable end of the pliable container for storage. Unfortunately, the rolled-up ends of such pliable containers generally tend to unroll between uses, which leads to the food items becoming stale prematurely.
Proposed solutions to this problem include providing various types of closure structures at the openable end to maintain the side walls of the container in a close bearing relationship for sealing purposes. For example, it is known to utilize a clip to prevent the openable container end from unrolling. Since such clips are completely separate from the container, they can be misplaced and are therefore often only used when readily available. In addition, these clips often tend to break and only directly maintain a small central section of the openable container end in a rather tight, closed condition. Zip-type closure arrangements have also become quite prevalent for use with certain types of bags. Such closure arrangements are considered advantageous in at least they generally extend entirely across the width of the openable end and are formed integral with the container. However, such closure arrangements are considered to be quite difficult to use, particularly for children and the elderly, due to the required dexterity. In addition, these closure arrangements do not provide an immediate indication that a complete seal has been established. Instead, the entire arrangement must be systematically sealed from one end of the opening to the other and if any portion is not sealed, the purpose of the entire closure can be completely compromised.
In addition to the need for providing a closure system for sealing closing an openable end of a pliable container, it is also considered advantageous to enhance the accessibility to an interior of a container when the container is opened. More specifically, when the container is opened, it is desirable to maintain the side walls of the container spaced apart, at least at the open end of the container, to permit easy access to the contents. Of course, neither clips nor zip-type closure systems perform this desired function.
Other types of closure arrangements for pliable containers have been proposed to perform both of these desired functions, such as that represented in U.S. Pat. No. 5,037,138. According to this patented arrangement, a snap-type closure mechanism includes a closure strip secured to one side wall of a pliable container, adjacent an openable end thereof. The closure mechanism is generally biased to a closed condition, but can be flexed outward along a centerline of the strip to maintain the container in an open condition. Merely squeezing the closure strip near the centerline causes the container to assume the closed condition.
The problem with such an arrangement is that it really only maintains a central portion of the container open an adequate amount, particularly since any biasing force tending to hold the container open essentially acts between side edge portions of the container and the closure strip. No closure structure is provided along the other side wall of the container to co-act with the closure strip, such that the degree to which the container can be held open is limited and the sealing effectiveness of the closure is minimized.
Based on the above, there exists a need in the art for a simple, inexpensive closure system for use with pliable containers which will enhance the accessibility to the contents when the containers are open and which can be effectively used to repetitively seal the containers.